Problem with IOS Cant play the external video files

Question

I have an external mp4 files to be playable in proxy chunked with php code, here's the Php code, and the code is working fine on android and desktop user, but getting stuck with IOS /iphone safari

<?php
ini_set('max_execution_time', 0);
$useragent = "Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.96 Safari/537.36";
$v = 192.168.xxx.xxx/bla..bla.mp4;
$ch = curl_init();
curl_setopt($ch, CURLOPT_VERBOSE, 1);
curl_setopt($ch, CURLOPT_TIMEOUT, 222222);
curl_setopt($ch, CURLOPT_URL, $v);
//curl_setopt($ch, CURLOPT_IPRESOLVE, CURL_IPRESOLVE_V4 );
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
curl_setopt($ch, CURLOPT_HEADER, true);
curl_setopt($ch, CURLOPT_FRESH_CONNECT, true);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 0);
curl_setopt($ch, CURLOPT_USERAGENT, $useragent);
curl_setopt($ch, CURLOPT_NOBODY, true);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$info = curl_exec($ch);
$size2 = curl_getinfo($ch, CURLINFO_CONTENT_LENGTH_DOWNLOAD);
header("Content-Type: video/mp4");
$filesize = $size2;
$offset = 0;
$length = $filesize;
if (isset($_SERVER['HTTP_RANGE'])) {
    $partialContent = "true";
    preg_match('/bytes=(\d+)-(\d+)?/', $_SERVER['HTTP_RANGE'], $matches);
    $offset = intval($matches[1]);
    $length = $size2 - $offset - 1;
} else {
    $partialContent = "false";
}
if ($partialContent == "true") {
    header('HTTP/1.1 206 Partial Content');
    header('Accept-Ranges: bytes');
    header('Content-Range: bytes '.$offset.
        '-'.($offset + $length).
        '/'.$filesize);
} else {
    header('Accept-Ranges: bytes');
}
header("Content-length: ".$size2);


$ch = curl_init();
if (isset($_SERVER['HTTP_RANGE'])) {
    // if the HTTP_RANGE header is set we're dealing with partial content
    $partialContent = true;
    // find the requested range
    // this might be too simplistic, apparently the client can request
    // multiple ranges, which can become pretty complex, so ignore it for now
    preg_match('/bytes=(\d+)-(\d+)?/', $_SERVER['HTTP_RANGE'], $matches);
    $offset = intval($matches[1]);
    $length = $filesize - $offset - 1;
    $headers = array(
        'Range: bytes='.$offset.
        '-'.($offset + $length).
        ''
    );
    curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
}
curl_setopt($ch, CURLOPT_VERBOSE, 1);
curl_setopt($ch, CURLOPT_TIMEOUT, 222222);
curl_setopt($ch, CURLOPT_URL, $v);
//curl_setopt($ch, CURLOPT_IPRESOLVE, CURL_IPRESOLVE_V4 );
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
curl_setopt($ch, CURLOPT_HEADER, false);
curl_setopt($ch, CURLOPT_FRESH_CONNECT, true);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, 0);
curl_setopt($ch, CURLOPT_USERAGENT, $useragent);
curl_setopt($ch, CURLOPT_NOBODY, false);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, false);
curl_exec($ch);
?>

how to make the file playable like in android/desktop

Any advice would be greatly appreciated.

Thanks,

Laura